Desulfurization of hydrocarbon streams

Abstract

A process for desulfurizing a hydrocarbon stream which includes at least 100 ppmw sulfur in the form of organic sulfur compounds, and C 4 -hydrocarbons. The hydrocarbon stream is contacted in the absence of added hydrogen with a fluidized bed of an acidic catalyst having a structure of ZSM-5, ZSM-11, ZSM-22, ZSM-23, ZSM-35, ZSM-48, MCM-22, MCM-36, MCM-49, zeolite Y, zeolite beta or mixtures thereof to convert the organic sulfur compounds to hydrogen sulfide. The catalyst contacts the hydrocarbon stream at a pressure of from 0.0 psig to about 400 psig, a temperature of from about 400° F. to about 900° F., and a weight hourly space velocity of from about 0.1 hr. -1 to about 10.0 hr. -1 . Thereafter, the hydrogen sulfide is removed from the hydrocarbon stream.

What is claimed is: 
     
       1. A process for desulfurizing a hydrocarbon stream including at least 100 ppmw sulfur in the form of organic sulfur compounds, and C 4  -hydrocarbons comprising the steps of: (a) pretreating said hydrocarbon stream to remove hydrogen sulfide;   (b) then contacting said hydrocarbon stream in the absence of added hydrogen with a fluidized bed of an acidic catalyst to convert said organic sulfur compounds to hydrogen sulfide; said catalyst contacting said hydrocarbon stream at a pressure of from 0.0 psig to about 400 psig, a temperature of from about 400° F. to about 900° F., and a weight hourly space velocity of from about 0.1 hr. -1  to about 10.0 hr. -1  ; and   (c) removing hydrogen sulfide produced in step (b) from said hydrocarbon stream.   
     
     
       2. The process of claim 1 wherein said hydrocarbon stream contains at least 300 ppmw sulfur in the form of said organic sulfur compounds. 
     
     
       3. The process of claim 1 in which said hydrocarbon stream comprises a light olefin component including C 4  -olefins. 
     
     
       4. The process of claim 3 in which said light olefin component contains at least 300 ppmw sulfur in the form of said organic sulfur compounds. 
     
     
       5. The process of claim 3 wherein a fluid catalytic cracking process produces said light olefin component. 
     
     
       6. The process of claim 1 wherein said catalyst is a zeolite catalyst. 
     
     
       7. The process of claim 6 wherein said zeolite comprises an intermediate pore size zeolite. 
     
     
       8. The process of claim 7 wherein said intermediate pore size zeolite has a structure of ZSM-5. 
     
     
       9. The process of claim 7 wherein said intermediate pore size zeolite has a structure of ZSM-5, ZSM-11, ZSM-22, ZSM-23, ZSM-35, ZSM-48, MCM-22 or mixtures thereof. 
     
     
       10. The process of claim 6 wherein said zeolite has a constraint index of 1 to 12. 
     
     
       11. The process of claim 6 wherein said zeolite comprises a large pore size zeolite. 
     
     
       12. The process of claim 11 wherein said zeolite comprises zeolite Y or zeolite beta. 
     
     
       13. The process of claim 1 wherein said hydrocarbon stream is contacted with said catalyst at a temperature of from about 600° F. to about 900° F. 
     
     
       14. The process of claim 13 wherein said hydrocarbon stream is contacted with said catalyst at a temperature of from about 700° F. to about 850° F. 
     
     
       15. The process of claim 14 wherein said catalyst is ZSM-5, ZSM-11, ZSM-22, ZSM-23, ZSM-35, ZSM-48 or mixtures thereof. 
     
     
       16. The process of claim 1 wherein said hydrocarbon stream is contacted with said catalyst at a temperature of from about 400° F. to about 750° F. 
     
     
       17. The process of claim 16 wherein said catalyst is MCM-22, MCM-36, MCM-49, zeolite Y, zeolite beta or mixtures thereof. 
     
     
       18. The process of claim 1 wherein said hydrocarbon steam is contacted with said catalyst at a pressure of from 50 psig to about 250 psig. 
     
     
       19. The process of claim 1 wherein said hydrocarbon stream is contacted with said catalyst at a weight hourly space velocity from about 0.1 hr. -1  to about 5.0 hr. -1 . 
     
     
       20. The process of claim 1 wherein at least 30% of said organic sulfur compounds are removed from said hydrocarbon stream. 
     
     
       21. The process of claim 1 wherein at least 50% of said organic sulfur compounds are removed from said hydrocarbon stream. 
     
     
       22. A process for desulfurizing a hydrocarbon stream including at least 100 ppmw sulfur in the form of organic sulfur compounds, and C 4  - hydrocarbons comprising the steps of: a) pretreating said hydrocarbon stream to remove hydrogen sulfide;   (b) contacting said hydrocarbon stream in the absence of added hydrogen with a fluidized bed of an acidic catalyst having a structure of ZSM-5, ZSM-11, ZSM-22, ZSM-23, ZSM-35, ZSM-48, MCM-22, MCM-36, MCM-49, zeolite Y, zeolite beta or mixtures thereof to convert said organic sulfur compounds to hydrogen sulfide; said catalyst contacting said hydrocarbon stream at a pressure of from 0.0 psig to about 400 psig, a temperature of from about 400° F. to about 900° F. and a weight hourly space velocity of from about 0.1 hr. -1  to about 10.0 hr. -1  ; and   (c) removing hydrogen sulfide produced in step (b) from said hydrocarbon stream.   
     
     
       23. The process of claim 22 wherein said catalyst comprises ZSM-5, ZSM-11, ZSM-22, MCM-49 ZSM-23, ZSM-35, ZSM-48 or mixtures thereof, and wherein said pressure is from about 50 psig to about 250 psig, said temperature is from about 700° F. to about 850° F. and said space velocity is from about 1.0 hr. -1  to about 5.0 hr. -1 . 
     
     
       24. The process of claim 22 wherein said catalyst has a structure of ZSM-5. 
     
     
       25. The process of claim 22 wherein said catalyst comprises MCM-22, MCM-36, MCM-49, zeolite Y, zeolite beta or mixtures thereof, and wherein said pressure is from about 50 psig to about 250 psig, said temperature is from about 400° F. to about 800° F. and said space velocity is from about 1.0 hr. -1  to about 5.0 hr. -1 .